Piriform News

The Piriform team would like to announce the latest release of CCleaner for Windows.

This minor update addresses Firefox and Edge issues reported by our community. If you have suggestions for what you'd like to see next, please drop by our forums and let us know in our suggestions area.

We are changing our default cleaning rules so that your recently used files and saved browser sessions aren't wiped without your explicit consent. These changes will take effect automatically for fresh installations of CCleaner, but we won't overwrite any of your existing preferences. To use the new default settings, go to the 'Cleaner' menu, right click on the 'Windows' and 'Applications' tabs and select 'Restore default state'.

Windows Explorer: Most Recently Used documents and other MRU files no longer cleaned by default

Following the security incident in September we have taken steps to improve our security across the board. Within CCleaner, this means the addition of an 'Emergency Updater' security feature that allows us to force a software update in a worse-case scenario. We have ring-fenced the updater in its own executable to allow it to operate independently from the main executable. The update check runs as a scheduled task in Windows.

Emergency Updater checks regularly to see if an emergency security update is available. If one is, it applies the update immediately. Checks only transmit 1-2 KB of data and generally an emergency update will consist of a differential patch roughly 500 KB in size.

The Piriform team would like to announce the latest release of CCleaner Cloud, which has had an agent update.

CCleaner Cloud version 1.08 has been released with a new digital signature to update our systems after the September 18th security notification.

This update applies to all versions of CCleaner Cloud (Free, Pro and Business).

Give it a try!If you are already a CCleaner Cloud user your installation will update automatically.

If you'd like to become a CCleaner Cloud user you can sign up by trialling our Pro version free-of-charge. We don't ask for card details because we believe in giving users a no fuss, no obligation trial. If at the end of your trial you don't wish to continue as a Pro user your account will automatically be converted to CCleaner Cloud Free. You'll then be able to manage up to 3 computers.Hear from us by email:If you haven't done so already, you can sign up to receive selected email communications, including news, product updates, case studies and special announcements, here.

We recently determined that older versions of our Piriform CCleaner v5.33.6162 and CCleaner Cloud v1.07.3191 had been compromised. We estimate that 2.27 million people used the affected software. We resolved this quickly and believe no harm was done to any of our users. This compromise only affected customers with the 32-bit version of the v5.33.6162 of CCleaner and the v1.07.3191 of CCleaner Cloud. No other Piriform or CCleaner products were affected. We encourage all users of the 32-bit version of CCleaner v5.33.6162 to download v5.34 here: download. We apologize and are taking extra measures to ensure this does not happen again.

Issue Summary: Our new parent company, the security company Avast, determined on the 12th of September that the 32-bit version of our CCleaner v5.33.6162 and CCleaner Cloud v1.07.3191 products, which may have been used by up to 3% of our users, had been compromised in a sophisticated manner. Piriform CCleaner v5.33.6162 was released on the 15th of August, and a regularly scheduled update to CCleaner, without compromised code, was released on the 12th of September. CCleaner Cloud v1.07.3191 was released on the 24th of August, and updated with a version without compromised code on September 15. The compromise could cause the transmission of non-sensitive data (computer name, IP address, list of installed software, list of active software, list of network adapters) to a 3rd party computer server in the USA. We have no indications that any other data has been sent to the server. Working with US law enforcement, we caused this server to be shut down on the 15th of September before any known harm was done. It would have been an impediment to the law enforcement agency’s investigation to have gone public with this before the server was disabled and we completed our initial assessment. Between the 12th and the 15th, we took immediate action to make sure that our Piriform CCleaner v5.33.6162 and CCleaner Cloud v1.07.3191 users were safe - we worked with download sites to remove CCleaner v5.33.6162, we pushed out a notification to update CCleaner users from v5.33.6162 to v5.34, we automatically updated those where it was possible to do so, and we automatically updated CCleaner Cloud users from v1.07.3191 to 1.07.3214.

We are continuing to investigate how this compromise happened, who did it, and why. We are working with US law enforcement in their investigation. A more technical description of the issue is on our Piriform blog at: www.ccleaner.com/news/blog. Again, we sincerely apologize for this and are committed to making sure nothing similar happens again. We encourage any user of the 32-bit version of CCleaner v5.33.6162 to download the latest version of Piriform CCleaner found here: www.ccleaner.com/ccleaner/download/standard.

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